Mouthguard



FIG. 1 is a top, front perspective view of a mouthguard showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a back view thereof; and,

FIG. 6 is a side view thereof. 

CLAIM The ornamental design for a mouthguard, as shown and described. 